A typical architecture of a memory cell may have a charging component, a sensing component, and a storage component. The storage component stores information represented by a given voltage level. The charging component programs and erases information stored in the memory cell. The sense component conveys the information stored in the memory cell during a read operation.
In memory designs where the transistors of multiple memory cells are switching at the same time, the peak current demand goes very high and the power supply may not be able to supply the instant current demand without generating excess noise. In that short period of time when the excess current demand is occurring, the transistors may not function properly. Moreover, the high peak current may induce noise into the memory system or any other block of electronic components sitting near that memory instance. Further, the high peak current may increase the electro migration in the power buses to cause other noise. Thus, when a memory recalls data from a large amount of non-volatile memory cells in parallel to corresponding volatile memory cells a lot of noise may be induced into this memory system.
In prior art system employing flash memories, the reading and writing operating voltages may typically be between 500 millivolts and 1000 millivolts. Generally, all of the flash memory cells are read from or written to as a single group. The noise generated from the single group read or write operations compared to sensing voltages and loading voltages used in the flash memory cell is only a small percentage of the data voltage levels stored in those cells. However, some non-volatile electrically alterable memory cells operate at a significantly lower stored data voltage level. At these lower storing and loading voltages, noise becomes a significant factor in design. Nonetheless, access time and speed to the information stored in these memory cells is also a design factor. In general, a memory should maintain a fast access rate, maintain that the data being transferred is accurate, and ensure that the data corruption by noise levels does not occur.
Some prior art memory systems get around this problem by simply adding a memory that is discrete from a chip, as a stand-alone unit. Some stand-alone memory units, such as a flash memory unit, operate on significantly higher voltages and therefore are not affected by what is commonly called transistor output switching current noise. Therefore, in the current technology of most stand-alone memories, controlling noise levels is not as important because that memory's operating voltages are significantly larger. However, these stand-alone memory units add an extra component into a design of a system, which then adds in extra cost. Some of these memory units may also be embedded into a System On a Chip design, however, that task creates multiple extra processing steps beyond what occurs in a standard fabrication logic process. The extra processing steps add more costs into making the System on a Chip.